A series of monomeric ruthenium polypyridyl complexes have been synthesized and characterized, their performance as water oxidation catalysts has evaluated. The diversity ligand environments how they influence rates reaction thermodynamics create a platform for catalyst design with controllable reactivity based on variations.

Artificial photosynthesis and the production of solar fuels could be a key element in future renewable energy economy providing solution to storage problem conversion. We describe hybrid strategy for water splitting based on dye sensitized photoelectrosynthesis cell. It uses derivatized, core-shell nanostructured photoanode with core high surface area conductive metal oxide film--indium tin or antimony oxide--coated thin outer shell TiO2 formed by atomic layer deposition. A...

The metal complex [(tpy)(Mebim-py)Ru II (S)] 2+ (tpy = 2,2 ′ : 6 ,2 ′′ -terpyridine; Mebim-py 3-methyl-1-pyridylbenzimidazol-2-ylidene; S solvent) is a robust, reactive electrocatalyst toward both water oxidation to oxygen and carbon dioxide reduction monoxide. Here we describe its use as single for CO 2 splitting, → + 1/2 O , in two-compartment electrochemical cell.

The performance of dye-sensitized solar and photoelectrochemical cells is strongly dependent on the light absorption electron transfer events at semiconductor–small molecule interface. These processes as well photo/electrochemical stability are dictated not only by properties chromophore metal oxide but also structure dye molecule, number surface binding groups, their mode to surface. In this article, we report photophysical electrochemical a series six phosphonate-derivatized [Ru(bpy)3]2+...

Significance Mesoporous SnO 2 /TiO core/shell nanostructured electrodes derivatized with a surface-bound Ru(II) polypyridyl-based chromophore–catalyst assembly are used for water splitting into H and O visible light in dye-sensitized photoelectrosynthesis cell. Photocurrents small applied bias among the highest reported. Stabilization of on surface TiO shell by using atomic layer deposition to deposit overlayers Al 3 or results long-term even phosphate buffer at pH 7.

Simple assembly: A "layer-by-layer" deposition of functionalized dyes/catalysts on the surfaces nanocrystalline oxides is introduced. The strategy general and offers considerable flexibility based phosphonate- or carboxylate-binding groups with ZrIV as bridging ions. resulting bilayer structures are capable supporting rapid intra-layer energy electron transfer (see picture).

Photoinduced formation, separation, and buildup of multiple redox equivalents are an integral part cycles for producing solar fuels in dye-sensitized photoelectrosynthesis cells (DSPECs). Excitation wavelength-dependent electron injection, intra-assembly transfer, pH-dependent back transfer on TiO2 were investigated the molecular assembly [((PO3H2-CH2)-bpy)2Rua(bpy-NH-CO-trpy)Rub(bpy)(OH2)]4+ ([TiO2–RuaII–RubII–OH2]4+; ((PO3H2-CH2)2-bpy =...

Water-stable, surface-bound chromophores, catalysts, and assemblies are an essential element in dye-sensitized photoelectrosynthesis cells for the generation of solar fuels by water splitting CO2 reduction to CO, other oxygenates, or hydrocarbons. Phosphonic acid derivatives provide a basis stable chemical binding on metal oxide surfaces. We report here efficient synthesis 4,4'-bis(diethylphosphonomethyl)-2,2'-bipyridine 4,4'-bis(diethylphosphonate)-2,2'-bipyridine, as well mono-, bis-,...

The oxidative stability of the molecular components dye-sensitized photoelectrosynthesis cells for solar water splitting remains to be explored systematically. We report here results an electrochemical study on ruthenium(II) polypyridyl complexes surface-bound fluorine-doped tin oxide electrodes in acidic solutions and, a lesser extent, as function pH and solvent with monitoring. Desorption occurs Ru(II) forms oxidation Ru(III) enhancing both desorption decomposition. Based long-term...

The synthesis, characterization, and redox properties are described for a new ruthenium-based chromophore-catalyst assembly, [(bpy)(2)Ru(4-Mebpy-4'-bimpy)Ru(tpy)(OH(2))](4+) (1, [Ru(a)(II)-Ru(b)(II)-OH(2)](4+); bpy = 2,2'-bipyridine; 4-Mebpy-4'-bimpy 4-(methylbipyridin-4'-yl)-N-benzimid-N'-pyridine; tpy 2,2':6',2"-terpyridine), as its chloride salt. assembly incorporates both visible light absorber catalyst water oxidation. With added ceric ammonium nitrate (Ce(IV), or CAN), 1 2,...

Single-electron activation of multielectron catalysis has been shown to be viable in catalytic water oxidation with stepwise proton-coupled electron transfer, leading high-energy precursors. For the blue dimer, cis,cis-[(bpy)2(H2O)RuIIIORuIII(H2O)(bpy)2]4+, first well-defined molecular catalyst for oxidation, 4e−/4H+ occurs give reactive precursor [(O)RuVORuV(O)]4+. This key intermediate is kinetically inaccessible at an unmodified metal oxide surface, where only available redox pathway...

Ein an nanoITO gebundenes Assoziat aus Rutheniumchromophor und -katalysator (siehe Bild) fungiert als Elektrokatalysator bei der Wasseroxidation, wobei in 0.1 M HClO4 O2 einem Überpotential von 230 mV entwickelt wird. Die Potentialantwort Elektrode spricht dafür, dass 3 e−/2 H+-oxidiertes [RuaIIIRubIVO]5+ die aktive Form des Assoziats ist. ITO=Indium-Zinn-Oxid.

The synthesis and analysis of a new amide-linked, dinuclear [Ru(bpy)2(bpy-ph-NH-CO-trpy)Ru(bpy)(OH2)]4+ (bpy = 2,2′-bipyridine; bpy-ph-NH-CO-trpy 4-(2,2′:6′,2″-terpyridin-4′-yl)-N-[(4′-methyl-2,2′-bipyridin-4-yl)methyl]benzamide) assembly that incorporates both light-harvesting chromophore water oxidation catalyst are described. With the saturated methylene linker present, individual properties retained including catalysis relatively slow energy transfer from excited state to catalyst.

The capture and storage of solar energy requires chromophores that absorb light throughout the spectrum. We report here synthesis, characterization, electrochemical, photophysical properties a series Ru(II) polypyridyl complexes type [Ru(bpy)2(N–N)]2+ (bpy = 2,2′-bipyridine; N–N is bidentate ligand). In this series, nature ligand was altered, either through increased conjugation or incorporation noncoordinating heteroatoms, as way to use electronic tune redox potentials, absorption spectra,...

Interfacial charge recombination dynamics in nanocrystalline SnO2 and TiO2 thin films sensitized with phosphonate-derivatized ruthenium chromophores (Ru(bpy)2(4,4′-(PO3H2)2bpy)]2+, RuP) have been investigated aqueous media by nanosecond transient absorption spectroscopy. Back electron transfer (BET) rates for RuP–SnO2 were observed to be 2–3 times greater than RuP–TiO2. Additionally, of RuP–TiO2 show a significant pH dependence, while only subtle influence is BET RuP–SnO2. Cyclic voltammetry...

Knowledge of electronic structures and transport mechanisms in dye-sensitized semiconductors is motivated by their ubiquity photoelectrochemical cells. In this work, optical spectroscopies are used to uncover the elementary dynamics initiated light absorption at such molecule–semiconductor interfaces (e.g., electron transfer nuclear relaxation). These processes explored a family ruthenium bipyridyl complexes aqueous solutions, wherein phosphonate groups bind molecules TiO2 nanocrystalline...

Dye-sensitized photoelectrosynthesis cells (DSPECs) represent a promising approach to solar fuels with solar-energy storage in chemical bonds. The targets are water splitting and carbon dioxide reduction by CO, other oxygenates, or hydrocarbons. DSPECs based on dye-sensitized (DSSCs) but photoexcitation driving physically separated fuel half reactions. A systematic basis for is available modular light absorption/excited-state electron injection, catalyst activation assembled integrated...

Significant rate enhancements are found for benzyl alcohol oxidation by the RuV═O3+ form of water catalyst [Ru(Mebimpy)(bpy)(OH2)]2+ [Mebimpy = 2,6-bis(1-methylbenzimidazol-2-yl)pyridine; bpy 2,2′-bipyridine] compared to RuIV═O2+ and with added bases due a new pathway, concerted hydride proton transfer (HPT).

Surface-bound, perylenediimide (PDI)-based molecular assemblies have been synthesized on nanocrystalline TiO2 by reaction of a dianhydride with surface-bound aniline and succinimide bonding. In second step, the Fe(II) polypyridyl complex [FeII(tpy-PhNH2)2]2+ was added to outside film, also Ultrafast transient absorption measurements in 0.1 M HClO4 reveal that electron injection into 1PDI* does not occur, but rather leads ultrafast formation redox-separated pair PDI•+,PDI•–, which decays...

Teen courts have grown rapidly in the United States despite little evidence of their effectiveness. A survival analysis 635 teen court and 186 regular diversion participants showed no significant differences recidivism, although program completers were half as likely to reoffend noncompleters. Older offenders survived significantly better than younger ones, girls boys. For full sample, increasing number sanctions resulted earlier reoffending. This effect disappeared when noncompleters...

Interfacial dynamics following photoexcitation of the water oxidation assembly [((PO3H2)2bpy)2RuII(bpy-bimpy)RuII(tpy)(OH2)]4+, −[RuaII–RubII–OH2]4+, on nanocrystalline TiO2 electrodes, starting from either −[RuaII–RubII–OH2]4+ or −[RuaII–RubIII–OH2]5+, have been investigated. Transient absorption measurements for TiO2–[RuaII–RubII–OH2]4+ in 0.1 M HPF6 neat trifluoroethanol reveal that electron injection occurs with high efficiency but hole transfer to catalyst, which electrochemical time...

Einfache Organisation: Die schichtweise Ablagerung funktionalisierter Farbstoffe/Katalysatoren auf der Oberfläche nanokristalliner Oxide, bei Phosphonat- und Carboxylatgruppen sowie ZrIV als Brückenionen eingesetzt werden, ist eine vielseitige Methode mit beträchtlicher Flexibilität. resultierenden Doppelschichtstrukturen zeichnen sich durch einen schnellen Energie- Elektronentransport zwischen den Schichten aus (siehe Bild).

A Ru(NH-NHC) complex with an open coordination site on the metal center adjacent to ligand N–H moieties has been synthesized and characterized. This exhibits unique reactivity upon reaction either CO2 or NaHCO3, yielding a formate-bridged bimetallic via spontaneous deoxygenation formal reduction at carbon. Dehydrogenation of formate leads Ru–carbamate species following carbon–nitrogen bond formation between moiety NHC ligand. opens up new pathways for is relevant H2 storage.

AbstractAbstractSingle vehicle traffic fatality data spanning the years 1982–1991 appear to support convergence hypothesis: that women are becoming more like men in their behaviors. However, diminishing differences between male and female fatalities do not a risk-taking model of convergence. Male drivers killed single crashes have reduced as measured by driving at night, on weekends, prior convictions crashes, drunken driving. Female risen because increased risk-taking; rather, greater...

Agrobacterium tumefaciens pathogenesis of plants is initiated with signal reception and culminates transforming the genomic DNA its host. The histidine sensor kinase VirA receives reacts to discrete signaling molecules for full induction genes necessary this process. Though many components process have been identified, precise mechanism how coordinates response host signals, namely phenols sugars, unknown. Recent advances molecular modeling allowed us test structure/function predictions...